"The McCanns can sleep well knowing they won't be arrested (at this stage)," the paper said, quoting a source in the forensics labs at the Policia Judiciara.

Scientific evidence - including DNA evidence - has been sent from Portugal to a specialty lab in Birmingham. The long-awaited results are not yet in.

However, the source said, the Policia Judiciara did not seal the area off properly when Madeleine disappeared because they did not use the correct technical equipment.

The accusation that police did not seal the area off properly has been leveled against the Policia Judiciara before - but this is the first time that a source from within the PJ has admitted it.

When specialists from the lab arrived on the scene, the source was quoted as saying, most of the evidence was already gone.

Worse still, the paper added, the McCanns' rented Renault Scenic and Robert Murat's car - as well as that of his friend Sergei Malinka - were contaminated with the fingerprints of members of the Policia Judiciara.

"We have excellent investigators, we have excellent resources in scientific terms, but we do not have equipment that isolates a place where a crime has occurred and makes it possible to collect all the necessary evidence to say what really happened."